How to download a file with progress with IdHTTP via https - delphi

Question

I'm trying to download a file using indy10 http components TIdHttp while getting the progress , I have just setted the libraries in the application folder while using the code for http URL it works and progress but with https it simply does nothing and it doesn't raises any exception :/
with TIdHTTP.Create(nil) do
begin
IOHndl:=TIdSSLIOHandlerSocketOpenSSL.Create(nil);
Request.BasicAuthentication:=True;
HandleRedirects:=True;
IOHandler:=IOHndl;
OnWork:=FOnWork;
OnWorkBegin:=FOnWorkBegin;
OnWorkEnd:=FOnWorkEnd;
Get(FUrl,FStream);
end;
Best Regards

Answer 1

First you have to create a small class to wrap the HTTP component:
unit IdHTTPProgressU;
interface
uses
Classes, IdBaseComponent, IdComponent, IdTCPConnection, IdTCPClient, IdHTTP, IdSSLOpenSSL;
{$M+}
type
TIdHTTPProgress = class(TIdHTTP)
private
FProgress: Integer;
FBytesToTransfer: Int64;
FOnChange: TNotifyEvent;
IOHndl: TIdSSLIOHandlerSocketOpenSSL;
procedure HTTPWorkBegin(ASender: TObject; AWorkMode: TWorkMode; AWorkCountMax: Int64);
procedure HTTPWork(ASender: TObject; AWorkMode: TWorkMode; AWorkCount: Int64);
procedure HTTPWorkEnd(Sender: TObject; AWorkMode: TWorkMode);
procedure SetProgress(const Value: Integer);
procedure SetOnChange(const Value: TNotifyEvent);
public
Constructor Create(AOwner: TComponent);
procedure DownloadFile(const aFileUrl: string; const aDestinationFile: String);
published
property Progress: Integer read FProgress write SetProgress;
property BytesToTransfer: Int64 read FBytesToTransfer;
property OnChange: TNotifyEvent read FOnChange write SetOnChange;
end;
implementation
uses
Sysutils;
{ TIdHTTPProgress }
constructor TIdHTTPProgress.Create(AOwner: TComponent);
begin
inherited;
IOHndl := TIdSSLIOHandlerSocketOpenSSL.Create(nil);
Request.BasicAuthentication := True;
HandleRedirects := True;
IOHandler := IOHndl;
ReadTimeout := 30000;
OnWork := HTTPWork;
OnWorkBegin := HTTPWorkBegin;
OnWorkEnd := HTTPWorkEnd;
end;
procedure TIdHTTPProgress.DownloadFile(const aFileUrl: string; const aDestinationFile: String);
var
LDestStream: TFileStream;
aPath: String;
begin
Progress := 0;
FBytesToTransfer := 0;
aPath := ExtractFilePath(aDestinationFile);
if aPath <> '' then
ForceDirectories(aPath);
LDestStream := TFileStream.Create(aDestinationFile, fmCreate);
try
Get(aFileUrl, LDestStream);
finally
FreeAndNil(LDestStream);
end;
end;
procedure TIdHTTPProgress.HTTPWork(ASender: TObject; AWorkMode: TWorkMode; AWorkCount: Int64);
begin
if BytesToTransfer = 0 then // No Update File
Exit;
Progress := Round((AWorkCount / BytesToTransfer) * 100);
end;
procedure TIdHTTPProgress.HTTPWorkBegin(ASender: TObject; AWorkMode: TWorkMode; AWorkCountMax: Int64);
begin
FBytesToTransfer := AWorkCountMax;
end;
procedure TIdHTTPProgress.HTTPWorkEnd(Sender: TObject; AWorkMode: TWorkMode);
begin
FBytesToTransfer := 0;
Progress := 100;
end;
procedure TIdHTTPProgress.SetOnChance(const Value: TNotifyEvent);
begin
FOnChance := Value;
end;
procedure TIdHTTPProgress.SetProgress(const Value: Integer);
begin
FProgress := Value;
if Assigned(FOnChance) then
FOnChance(Self);
end;
end.
I wont go in to details with the calss: Just say that it bacally wraps a TIdhttp component in and assign the 3 events: OnBegin, onWork and OnEnd
The Method DownloadFile does the actually download,
Then when you have to use it you could do like this:
Place a Button and a PrograssBar on an empty form. Add IdHTTPProgressU to the uses list.
Declare a vaiable of TIdHTTPProgress and a local onChangeEvent
Your form definition should lokke like this:
type
TForm1 = class(TForm)
Button1: TButton;
ProgressBar1: TProgressBar;
procedure FormCreate(Sender: TObject);
procedure Button1Click(Sender: TObject);
private
procedure IdHTTPProgressOnChange(Sender : TObject);
public
IdHTTPProgress: TIdHTTPProgress;
end;
Then you just have to implement the methods:
{ TForm1 }
procedure TForm1.Button1Click(Sender: TObject);
begin
IdHTTPProgress.OnChange := IdHTTPProgressOnChance;
IdHTTPProgress.OnChance := IdHTTPProgressOnChance;
IdHTTPProgress.DownloadFile('https://wordpress.org/latest.zip', 'latest.zip');
end;
procedure TForm1.FormCreate(Sender: TObject);
begin
IdHTTPProgress := TIdHTTPProgress.Create(Self);
end;
procedure TForm1.IdHTTPProgressOnChance(Sender: TObject);
begin
ProgressBar1.Position := TIdHTTPProgress(Sender).Progress;
Application.ProcessMessages;
end;
Thats about it. Give it at try.